1. Field of the Invention
The present invention relates to window molding members for automobiles, having a cross section which varies in the longitudinal direction thereof, as well as a method of manufacturing such molding members.
2. Description of the Related Art
Typically, window molding members are used in combination with automobiles including a body panel with an outer surface, a flange recessed from the outer surface, and a shoulder portion connecting the flange with the outer surface. The flange of the body panel serves to mount a window plate thereon, with the peripheral edge of the plate opposed to the shoulder portion of the body panel leaving a gap therebetween.
A number of kinds of window molding members, adapted to satisfy various functional and/or ornamental requirements, are known and widely used for automobiles. Among others, U.S. Pat. Nos. 4,757,659 and 4,757,660 each discloses a window molding member having a crosssection which varies in the longitudinal direction of the molding member. This molding member includes an upper segment to extend along the upper edge of the window plate, a pair of side segments to extend along the side edges of the window plate, and a pair of corner segments integrally and continuously connecting the upper and side segments with each other in the longitudinal direction of the molding member.
In the known molding members mentioned above, each segment includes a main body adapted to cover the gap between the peripheral edge of the window plate and the shoulder portion of the body panel. The main body is provided with first and second lip sections on both sides, of which the first lip section is adapted to be brought into contact with the outer surface of the body panel. Each segment further includes a leg section which is integral with, and projects from, the main body to extend into the gap. The leg section is provided, on its one side, with first and second support webs to project toward the window plate. The first web on the leg section cooperates with the second lip section of the main body to form channels along the side segments for guiding the flow of rain water on the window plate, and to form a first groove for accommodating the upper edge of the window plate. The second web, in turn, cooperates with the first web along the side segments to form second grooves for accommodating the side edges of the window plate, and is removed away along the upper segment, together with a portion of the leg section.
With such an arrangement of the known molding members, the second lip section of the main body for the upper segment is adapted to be brought into contact with the window plate along the upper edge thereof, and thus serves as a flush outer surface of the automobile body along the upper edge of the window plate. The second lip section of the main body for the side segments achieves the function of preventing rain water on the window plate from flowing onto side windows across the side segment and neighbouring body panel portion (or pillar) by guiding the rainwater so as to flow along the channels without disturbing the driver's sight through the side windows.
In order to manufacture such molding members, a synthetic resin material is extruded from an extrusion die head into a continuous body of a crosssection which is constant throughout the entire length. Subsequently, the continuous body is cut into individual blank bodies with a predetermined length of a molding member. Each blank body is then subjected to removal of the first web along the regions corresponding to the corner segments, and also to removal of the second web and a part of the leg section along the region corresponding to the upper segment. A time-consuming delicate operation is required to effect the above-mentioned local cutting of the webs accurately, so that it is difficult to improve the manufacturing productivity and to significantly reduce the cost.
Moreover, since the first and second grooves have to be aligned with each other to accommodate the edge of the window plate, the corner segment tends to be excessively deformed when inserting the edge of the window plate into the grooves, and cannot be readily inserted into the gap between the shoulder portion of the body panel and the window plate. The deformed regions of the molding member are often apparently visible from outside, thereby significantly deteriorating the appearance.